Integrated Management of Early Blight (Alternaria solani) in Tomato (Solatium fycopersicum) in Arbaminch Areas, Southwestern Ethiopia

Abstract

Tomato early blight (Alternaria solani) is an important disease of tomato that reduces quantity and quality of fruit yield. Field experiments were conducted in 2016 and 2017 cropping seasons with the objective to evaluate the effect of varieties and fungicide application frequencies on early blight epidemics, total fruit yield and yield components. Treatments included four tomato varieties with different resistance levels and four foliar fungicide spray frequencies alone and in combination, including unsprayed plots as control. The treatments were arranged factorially in a randomized complete block design (RCBD) with three replications. The integrated use of tomato varieties with fungicide spray frequencies significantly reduced early blight epidemics and increased fruit yield parameters. A minimum mean disease severity was calculated for tomato varieties evaluated in the order of ART tomato d2, Roma VF, Bisholla and Melkasholla at 61 days after planting in four times fungicide sprayed plots compared to unsprayed plots in 2016 cropping season. A similar trend was observed in 2017 cropping season. The highest (12.54- 17.79%-days) rAUDPC values were calculated for unsprayed plots in 2016 and 15.71-22.16%- days during 2017 cropping season. Roma VF produced the highest (49.15 t h a '1) and Melkasholla gave the lowest (18.71 t ha ') mean marketable fruit yields, with three times fungicide spray frequencies in both cropping seasons. The study indicated that the inherent genetic potential of tomato varieties is complemented by foliar application of ridomil fungicide that contributed to low blight epidemics and high fruit yield, and provided higher net benefit with optimum marginal rate of return. It is commendable to screen additional tomato varieties and fungicides to come up with reliable recommendation against early blight for sustainable tomato production in the study area and other locations with similar agro-ecologies.